For well completion, a tubing hanger with a tubing string thereon is releasably connected to a running tool and lowered within a well for landing on a wellhead member. Hydraulic control fluid passages in the wellhead member and the tubing hanger are aligned in the landed position of the tubing hanger for the supply of the hydraulic control fluid to the tubing hanger. Hydraulic control fluid lines normally extend from the tubing hanger to selected downhole control members such as a downhole safety valve or a downhole chemical injection member for actuation of the downhole control members. Various prior art hydraulic fluid connectors or couplings have been provided heretofore between the wellhead member and the tubing hanger for the supply of hydraulic control fluid to the tubing hanger when landed on the wellhead member. For example, U.S. Pat. No. 5,465,794 dated Nov. 14, 1995 and U.S. Pat. No. 5,555,935 dated Sep. 17, 1996 disclose such fluid connectors.
Oftentimes, it is desirable that hydraulic control fluid be supplied, or have the capability of being supplied, to certain downhole control members, such as downhole safety valves, before the tubing hanger is landed on the wellhead member and while the running tool is lowering the tubing hanger within the wellhead member. For this purpose the hydraulic control fluid circuitry extends through a running tool for the supply of hydraulic control fluid to the tubing hanger and the downhole control members. The running tool is disconnected from the tubing hanger after landing of the tubing hanger on the wellhead member and it is necessary to seal the hydraulic control fluid port in the tubing hanger adjacent the running tool so that leakage does not occur. It is also possible that heavy well fluids in the wellbore might leak into the control fluid port and the associated fluid passage if not adequately sealed off.